Prevalence of antiphospholipid antibodies among patients with chronic thromboembolic pulmonary hypertension

In most cases of acute pulmonary embolism, fbrinolysis of the embolus takes place, restoring blood fow and normalizing hemodynamic parameters. However, in a minority of patients, a residual organized clot remains adherent to the pulmonary vasculature which, over time, results in a progressive increase in pulmonary vascular resistance. This condition, known as chronic thromboembolic pulmonary hypertension (CTEPH), is a rare complication of pulmonary embolism that is characterized by the presence of persistent and organized thrombi in the proximal pulmonary arteries [1, 2]. Poor thrombus resolution due to inadequate fbrinolysis and/or recurrent thrombosis likely predispose towards the development of CTEPH. However, why only a small subset of patients go on to develop CTEPH following acute pulmonary embolism remains uncertain.